The traditional implantable cardiac pacemaker includes a pulse generator device to which one or more flexible elongate lead wires are coupled. The device is typically implanted in a subcutaneous pocket, remote from the heart, and each of the one or more lead wires extends therefrom to a corresponding electrode, coupled thereto and positioned at a pacing site, either endocardial or epicardial. Mechanical complications and/or MRI compatibility issues, which are sometimes associated with elongate lead wires and well known to those skilled in the art, have motivated the development of implantable cardiac pacing devices that are wholly contained within a relatively compact package for implant in close proximity to the pacing site, for example, like a device 100, which is shown in FIG. 1, implanted within the right ventricle RV of the heart. FIG. 1 illustrates device 100 having been deployed out from a distal portion of a standard guiding catheter 150, which has been maneuvered up through the inferior vena cava IVC and into the right ventricle RV from the right atrium RA, according to methods known in the art of interventional cardiology. With further reference to FIG. 1, an hermetically sealed housing 105, preferably formed from a biocompatible and biostable metal such as titanium, contains a pulse generator, or an electronic controller (not shown), to which an electrode 111 is coupled, for example, by a hermetic feedthrough assembly (not shown) like those known to those skilled in the art of implantable medical devices. FIG. 1 further illustrates device 100 including a fixation member 115, which engages tissue at the implant site to secure device 100 thereto so that electrode 111 is held in intimate contact with the tissue at the site. Housing 105 may be overlaid with an insulative layer, for example, medical grade polyurethane, parylene, or silicone, and a portion of housing 105 from which the insulative layer is removed, may be employed as another electrode to function in conjunction with electrode 111 for ventricular bipolar pacing and sensing.